The present invention relates to spin control systems for vehicles generally and more particularly to a novel spin control system for an engine-driven, multi-wheeled vehicle.
Generally speaking, wheel spin in a driven wheel of a vehicle, such as an automobile, truck, or the like, is an undesirable condition. Accordingly, it is typically desirable to counteract the spin condition while in its incipiency before the spinning wheel can accelerate to a very high rotational velocity. Heretofore, various types of spin control systems have been proposed and developed.
The present invention is directed to improvements in spin control systems and provides a spin control system which is readily adaptable to virtually all currently manufactured vehicles with a minimum of revision to existing components in those vehicles. The present invention is especially well suited to mass production application, and results in a minimum addition to the vehicle cost while providing important advantages when the vehicle is in use. In the preferred embodiment of the spin control system according to the present invention, incipient wheel spin at one of the driven rear wheels of the vehicle is detected by comparing the average rotational speed of the rear wheels with the rotational speed of a free-running, or undriven, front wheel of the vehicle. The respective speed signals are provided by respective wheel speed sensors. When the average speed of the driven wheels exceeds the speed of the free-running wheel by a predetermined amount, thereby indicating that one or both of the driven wheels are in an incipient spin condition, an electronic circuit to which the wheel speed sensors are coupled develops a spin signal indicative of the incipient spin condition. A normally closed solenoid-actuated valve is mounted on the intake manifold of the engine and is arranged to open in response to the spin signal. Upon opening of the intake manifold valve, the intake manifold of the engine is vented to atmosphere. By venting the intake manifold in this fashion, intake manifold vacuum is reduced thereby reducing the flow of air-fuel mixture from the carburetor to the cylinders of the engine. Accordingly, the engine is effectively throttled down even through the carburetor throttle valve is in a position which otherwise would cause continued, or even increased, air-fuel mixture to be supplied to the engine cylinders. In turn, the power input to the incipiently spinning wheel is reduced. Thus, the spin control system of the present invention provides automatic spin control of the driven wheels of the vehicle thereby eliminating wheel spin and attendant adverse consequences thereof.
Other features and advantages of the present invention along with the aforementioned features and advantages will be seen in the ensuing description and claims which are to be taken in conjunction with the accompanying drawings.